Interference often hinders performance of communication systems. One type of interference often encountered by a user within a communication system is interference generated by the transmissions of other users. This is typically caused by many users transmitting within the same frequency band, and is referred to as co-channel interference. In order to reduce co-channel interference many communication systems employ a frequency reuse pattern, where transmitters in adjacent cells transmit on different frequencies. However, given the price of spectrum, future communications systems will be characterized by aggressive frequency reuse patterns that will result in significantly increased levels of co-channel interference.
Notwithstanding the above, more and more system operators are taking advantage of unlicensed frequency bands for transmitting information. Because the number of transmitters within an unlicensed frequency band is not restricted, there exists the potential of greatly increased co-channel interference. Additionally, because operators within the unlicensed band do not have to synchronize to a common source, typical co-channel interference is asynchronous in that the interfering signal does not align in time with the desired signal.
Because co-channel interference can greatly reduce the efficiency of a communication system, and because co-channel interference can be both synchronous and asynchronous, a need exists for a method and apparatus for reducing both synchronous and asynchronous co-channel interference within a communication system.